Noncommutative 6D Gauge Higgs Unification Models

The influence of higher dimensions in noncommutative field theories is considered. For this purpose, we analyze the bosonic sector of a recently proposed 6 dimensional SU(3) orbifold model for the electroweak interactions. The corresponding noncommutative theory is constructed by means of the Seiberg-Witten map in 6D. We find in the reduced bosonic interactions in 4D theory, couplings which are new with respect to other known 4D noncommutative formulations of the Standard Model using the Seiberg-Witten map. Phenomenological implications due to the noncommutativity of extra dimensions are explored. In particular, assuming that the commutative model leads to the standard model values, a bound -5.63 10^{-8} GeV^{-2}< theta <1.06 10^{-7}GeV^{-2} on the corresponding noncommutativity scale is derived from current experimental constraints on the S and T oblique parameters. This bound is used to predict a possibly significant impact of noncommutativity effects of extra dimensions on the rare Higgs boson decay H-> gamma gamma.Comment: Latex file, 11 pages, 1 figur

Low X-Ray Luminosity Galaxy Clusters: Main goals, sample selection, photometric and spectroscopic observations

We present the study of nineteen low X-ray luminosity galaxy clusters (L$_X \sim$ 0.5--45 $\times$ $10^{43}$ erg s$^{-1}$), selected from the ROSAT Position Sensitive Proportional Counters (PSPC) Pointed Observations (Vikhlinin et al. 1998) and the revised version of Mullis et al. (2003) in the redshift range of 0.16 to 0.7. This is the introductory paper of a series presenting the sample selection, photometric and spectroscopic observations and data reduction. Photometric data in different passbands were taken for eight galaxy clusters at Las Campanas Observatory; three clusters at Cerro Tololo Interamerican Observatory; and eight clusters at the Gemini Observatory. Spectroscopic data were collected for only four galaxy clusters using Gemini telescopes. With the photometry, the galaxies were defined based on the star-galaxy separation taking into account photometric parameters. For each galaxy cluster, the catalogues contain the PSF and aperture magnitudes of galaxies within the 90\% completeness limit. They are used together with structural parameters to study the galaxy morphology and to estimate photometric redshifts. With the spectroscopy, the derived galaxy velocity dispersion of our clusters ranged from 507 km~s$^{-1}$ for [VMF98]022 to 775 km~s$^{-1}$ for [VMF98]097 with signs of substructure. Cluster membership has been extensively discussed taking into account spectroscopic and photometric redshift estimates. In this sense, members are the galaxies within a projected radius of 0.75 Mpc from the X-ray mission peak and with cluster centric velocities smaller than the cluster velocity dispersion or 6000 km~s$^{-1}$, respectively. These results will be used in forthcoming papers to study, among the main topics, the red cluster sequence, blue cloud and green populations; the galaxy luminosity function and cluster dynamics.Comment: 13 pages, 6 tables, 9 figures. Uses emulateapj. Accepted for publication in The Astronomical Journal. Some formatting errors fixe

Determinación de algunas variables sanguíneas y su relación con el ejercicio de equinos fina sangre de carrera en entrenamiento competitivo

Se evaluaron las concentraciones sangu&iacute;neas de cortisol, glucosa y la relaci&oacute;n neutr&oacute;filo: linfocito (N: L) en 15 equinos Fina Sangre de Carrera (FSC) sometidos a dos tipos de ejercicio, distribuidos seg&uacute;n tipo de trabajo realizado, en 3 grupos de 5 animales cada uno, Grupo I: control, sin ejercicio, Grupo II: galope de 1000 metros y Grupo III: trabajo competitivo, galope de 600 metros seguido de 400 metros a velocidad supramaximal. De cada animal se extrajeron 2 muestras de sangre, antes del ejercicio (T0) y a las 2 horas post ejercicio (T1). Se determinaron las concentraciones plasm&aacute;ticas de cortisol (RIA), glucosa (espectrofotometr&iacute;a por t&eacute;cnica enzim&aacute;tica), y se realiz&oacute; un recuento leucocitario (contador hematol&oacute;gico autom&aacute;tico). Los valores se expresaron mediante media y D.E. Las variaciones por efecto del tiempo, grupo e interacci&oacute;n grupo por tiempo, se determinaron con ANDEVA con un intervalo de confianza de 95% y nivel de significancia de p&le;0,05.La intensidad del ejercicio fue la suficiente para generar un aumento significativo de la glicemia en los Gr. II y III al T1; solo el grupo III fue significativamente mayor al grupo I al T1. La concentraci&oacute;n plasm&aacute;tica de cortisol dentro de grupo, present&oacute; una disminuci&oacute;n significativa para el T1 del Gr. II, respecto de su T0. La relaci&oacute;n N:L, entre grupos al T0 el Gr. II fue significativamente mayor que los otros grupos; al comparar los valores dentro de grupo, mostraron una disminuci&oacute;n significativa en el Gr. II. La mayor concentraci&oacute;n basal de cortisol y la mayor relaci&oacute;n N: L fue en el grupo II. El tener un mayor descenso del cortisol plasm&aacute;tico y de la relaci&oacute;n N: L en T1 respecto de T0, refleja que la intensidad del ejercicio al que fue sometido es inferior al del grupo III. Los resultados descritos permitir&iacute;an concluir que la respuesta del organismo al ejercicio f&iacute;sico tiene directa relaci&oacute;n con el tipo de trabajo al cual es sometido el animal y la adaptaci&oacute;n de &eacute;ste al entrenamiento

Twisted Covariant Noncommutative Self-dual Gravity

A twisted covariant formulation of noncommutative self-dual gravity is presented. The formulation for constructing twisted noncommutative Yang-Mills theories is used. It is shown that the noncommutative torsion is solved at any order of the $\theta$-expansion in terms of the tetrad and some extra fields of the theory. In the process the first order expansion in $\theta$ for the Pleba\'nski action is explicitly obtained.Comment: 23+1 pages, no figures, corrected typos, references and Appendix B is adde

Plasmon enhanced energy-transfer up-conversion in Yb3+-Er3+ co-doped LiNbO3 crystal

We have analyzed the effect of linear chains of metallic Ag nanoparticles on the optical properties of a periodically poled Yb 3+ -Er 3+ co-doped LiNbO 3 crystal. By exploiting the broad plasmonic response supported by linear chains of strongly coupled Ag nanoparticles, we demonstrate a 50% of enhancement of the up-converted Er 3+ emission under excitation in the f-f transition of Yb 3+ ions. The observed intensification is explained in terms of the broad plasmonic spectral response supported by the Ag chains, which overlaps both the Er 3+ visible emissions and the Yb 3+ absorption band, and the two-photon character of the Yb 3+ → Er 3+ energy-transfer up-conversion process. The results are of interest for applications involving luminescence up-conversion such as sensing, solar energy conversion, biological imaging or solid-state nanolasersThis work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under project MAT2013- 43301-R and Comunidad de Madrid under grant S2013/MIT-274

Opinión de egresados en enfermería sobre la congruencia de los contenidos curriculares con los requerimientos laborales

ResumenLos perfiles profesionales de los egresados en área de la salud, y en particular de enfermería, requieren ajustarse a la compleja interacción que demandan las necesidades sociales y las exigencias del mercado laboral. Esto crea la necesidad de identificar fortalezas y debilidades durante su formación profesional a través de la sistematización de estudios de egresados, los cuales orientan a la mejora continua de los programas educativos, para facilitar la incorporación y desarrollo de los(as) egresados(as) en el ámbito laboral.ObjetivoDescribir la opinión de los egresados de enfermería de la Universidad Autónoma de Tlaxcala sobre la congruencia de los contenidos curriculares y requerimientos laborales al ofrecer el cuidado profesional.Material y métodosEstudio descriptivo, transversal. Incluyó 84 egresados de 3 generaciones, seleccionados por muestreo simple aleatorio. Se empleó un cuestionario adecuado y estructurado con base en la propuesta de la Asociación Nacional de Universidades e Instituciones de Educación Superior de 1998, organizado en 6 apartados.ResultadosEl 87% opinan que los contenidos curriculares son congruentes con las actividades que realizan al ofrecer el cuidado, el 86% perciben satisfacción de sus conocimientos, el 85% se consideran bien aceptados laboralmente, el 95% aprecian relevante su desempeño laboral, el 66% son contratados en 2.° y 3.er nivel de atención en el sector salud.ConclusionesLos egresados consideran que existe congruencia entre los contenidos curriculares con el desempeño profesional; se ubican mayormente en áreas asistenciales del 2.° y 3.er nivel de atención, y perciben satisfacción de los conocimientos adquiridos y aceptación laboral.AbstractProfessional profiles of graduates from the health areas, and particularly those from nursing, require adjustments in order to meet the complex interactions which social needs and labor market characteristics demand. This situation creates the need to identify strengths and weaknesses in the formation of these graduates. By systematizing and continuously improving their studies, a successful incorporation and development into the complex labor markets is more likely to be achieved.ObjectiveTo describe the opinion which the nursing graduates from the Tlaxcala Autonomous University have on the congruency of the curricular contents and the working requirements while providing professional care.Materials and methodsDescriptive and transversal study which included 84 graduates from 3 generations who were selected by random simple sampling, and which used a structured and convenient questionnaire following the 1998 ANUIES proposal organized in 6 dominions.Results87% of the participants opined the curricular contents are congruent with the activities they do while providing care; 86% perceive satisfaction with their knowledge; 85% consider they are well fit regarding labor; 95% consider their working performance relevant; 66% are hired into the Health Sector's 2nd and 3rd levels of attention.ConclusionsThere is congruency between the curricular contents and their professional performance; the graduates are mainly located within the assisting areas of the 2nd and 3rd levels of attention; they feel satisfied with their knowledge and perceive labor acceptance

Evaluación de la peligrosidad sísmica en España para aplicaciones relacionadas con la seguridad nuclear. Resultados preliminares.

En este trabajo se presentan los avances realizados en el marco del proyecto “Evaluación de la Peligrosidad Sísmica en España para aplicaciones relacionadas con la seguridad nuclear” financiado por el Consejo de Seguridad Nuclear. La finalidad última del proyecto es ahondar en el conocimiento de la peligrosidad sísmica y de su incertidumbre en los emplazamientos de instalaciones críticas como instalaciones nucleares y almacenamientos de residuos radiactivos en nuestro país. Con ese propósito, una primera fase del proyecto está destinada a recopilar y estructurar toda la información generada en proyectos previos financiados por el CSN (DAÑOS, SIGMA, PRIOR, EXPEL y DATACIÓN) concerniente a estudio de fallas activas, análisis de paleosismicidad, catálogos sísmicos y de movimiento fuerte del suelo, etc.. Esta información está siendo integrada y unificada en una Base de Datos y en un Sistema de Información Geográfica. Paralelamente, el código informático desarrollado en el proyecto EXPEL está siendo actualizado para desarrollar cálculos de peligrosidad sísmica siguiendo la metodología PSHA de una forma eficiente, incluyendo formulación de un árbol lógico, cuantificación de incertidumbres epistémicas y aleatorias, análisis de sensibilidad de diferentes opciones en los resultados y desagregación. Los resultados preliminares del proyecto son presentados en esta comunicación, dando una orientación hacia futuros desarrollos y toma de decisiones relacionados con la seguridad nuclear

Crossing the phantom divide in an interacting generalized Chaplygin gas

Unified generalized Chaplygin gas models assuming an interaction between dark energy and dark matter fluids have been previously proposed. Following these ideas, we consider a particular relation between dark densities, which allows the possibility of a time varying equation of state for dark energy that crosses the phantom divide at a recent epoch. Moreover, these densities decay during all the evolution of the Universe, avoiding a Big Rip. We find also a scaling solution, i.e. these densities are asymptotically proportional in the future, which contributes to the solution of the coincidence problem.Comment: Improved version, 10 pages, 4 figures, References adde

Retrieval of spatio-temporal distributions of particle parameters from multiwavelength lidar measurements using the linear estimation technique and comparison with AERONET

The results of the application of the linear estimation technique to multiwavelength Raman lidar measurements performed during the summer of 2011 in Greenbelt, MD, USA, are presented. We demonstrate that multiwavelength lidars are capable not only of providing vertical profiles of particle properties but also of revealing the spatio-temporal evolution of aerosol features. The nighttime 3β + 1α lidar measurements on 21 and 22 July were inverted to spatio-temporal distributions of particle microphysical parameters, such as volume, number density, effective radius and the complex refractive index. The particle volume and number density show strong variation during the night, while the effective radius remains approximately constant. The real part of the refractive index demonstrates a slight decreasing tendency in a region of enhanced extinction coefficient. The linear estimation retrievals are stable and provide time series of particle parameters as a function of height at 4 min resolution. AERONET observations are compared with multiwavelength lidar retrievals showing good agreement